Miniature switch



P. REITLER July 23, 1957 MINIATURE SWITCH 2 Sheets-Shea*l 1 Filed Oct.19, 1954 /NVENTOR ,PAUL RE/ T 5R ATTO NEV July 23, 1957 P. REITLER2,800,546

MINIATURE SWITCH Filed Oct. 19, 1954 2 Sheets-Sheet 2 i I /gi e 1| 5, 5253 /Nl/E/VTO PAUL PE/TLER BV A TTORNEV Laagste Q@ Patented July 23, 1957nur..

MHNEATURE SWETCH laul Reider, Kew Gardens, N. Y.

Application ctober 19, 1954, Serial No. 463,110

4 Claims. (Cl. Zilli-67) This invention relates to switching devices ofthe socalled miniature and subminiature type.

The object of the present invention is the provision of a switchmechanism of the above mentioned type which is simple and rugged inconstruction, cheap to manufacture and capable of effecting a greatnumber of switching operations in a positive manner.

A novel feature of the present invention resides in the provision of acasing of insulating molded material constructed of two co-operatingsections forming a housing for the switch mechanism, the sections havinginter-fitting portions for readily locating wire terminals and othercooperating parts of the switch mechanism in proper relation to eachother in addition to means serving for securing the two sectionstogether, following the assembly of the switch mechanism in the housing.

Another novel feature resides in the use of one of the switch wireterminals for pivotally mounting a conductor member and a contactcarrying conductor member movable in position for successively engagingcontacts carried by two other wire terminals of the switch, dependingupon the movement of the contact carrying conductor member as effectedby the operation of means in the forni of a plunger member litted forsliding movement in one of the sections of the switch housing inco-operation with a cornpression spring compressed by the operation ofthe plunger member from normal to operated position.

Another novel feature of the invention resides in the pivoting of theconductor members in a manner to cause the tensioning of a spring uponthe operation of the plunger member so as to cause the engagement of thecontact carrying conductor member with a stationary contact at one endof the other wire terminal for normally establishing an electricalconnection with a snap action, the engaged contact pressure therebetweenbeing dependent upon the normal tension of the spring in both operatingdirections of the contact carrying conductor member.

Another novel feature resides in securing one end of the tension springto one of the conductor members and to adjustable means in the housing,such means serving for hunting the switching movement of the conductormembers toward their normal position effected by the action of thetension spring independently of the continued operation of the plungermember.

Other novel features and advantages of the invention will appear fromthe following description and by the claims appended thereto, referencebeing had to the accompanying drawing in which:

Fig. l is an assembly view of the switching device of the inventionshown in perspective,

Fig. 2 is a vertical longitudinal section showing the plunger member innormal position and one of the contacts carried by the movable conductormember in engaged relation with the contact of one of the terminals,

Fig. 3 is a horizontal longitudinal sectional view taken on line 3-3 ofFig. 2,

Fig. 4 is another vertical longitudinal section showing the plungermember and the conductor members actuated thereby in the operatedposition with the contact carrying conductor member in engagement withthe contact of the second wire terminal,

Fig. 5 is a vertical cross sectional view taken on line 5-5 of Fig. 4,

Fig. 6 is a perspective view of a modification of the switching deviceof the invention showing the two sections in assembled relation, t

Fig. 7 is a front view of one of the housing sections showing theoperating parts in normal position, and

Fig. 8 is a top view of a detail of the switch mechanism showing amodification of the spring tensioned by the pivotal movement ,of theconductor members for a1- ternatively engaging the contact carryingconductor member with the wire terminals with a snap action.

The switching device of the present invention, as shown in Fig. l,consists of a housing formed of two sections 1t) and 11 constructed, forexample, of phenol plastic material. The section 10, which forms thecover portion of the housing, is provided with a relatively thick wallportion 12 having a cylindrical opening or bore 14 serving as a guidingelement for a plunger member 13 provided for operating the switchmechanism in a manner which will be hereinafter described in detail, theplunger member being provided with a head portion so as to prevent suchplunger from sliding out of the housing.

The sections and 11 are formed With substantially V-shaped registeringportions 15 and 16 at their ends for receiving the pins 17 and 18serving for holding the two sections in assembled relation to each otherfollowing the assembly of the switch mechanism, while the section 11which forms the base of the housing is provided with two openings OP forreceiving screws not shown serving for securing the switch to anydesired operating machine part of a machine with which it may be used.

Wire terminals as 19, 20 and 2l, and a metallic bushing 22 are embeddedin the molded insulating material forming the base or mounting section11 and are thereby anchored in proper spaced relation to each other,while a bore 23 serves for housing and readily locating a compressionspring 24 in coaxial alignment relative to plunger 13. The compressionspring 24 is normally compressed between a conductor member 25 and thebottom of bore Z3 to serve for holding such conductor in normalnonoperated position, as shown in Fig. 2, against the T shaped head of ascrew threaded stud 29 engaging the bushing 22, the other end ofconductor member 25 being provided With a rectangularly shaped slot 26,best seen in Fig. 3, engaged by a similarly shaped end portion 27 ofwire terminal 19, forming shoulder portions on the sides of theprotruding lug 27 against which the conductor member 25 abuts to serveas a pivot for the latter.

The free end of conductor member 25, as best seen in Figs. 2, 3 and 4,is formed with two prong portions eX- tending lengthwise to the oppositeside of the screw threaded stud 29 and are bent upwardly for engagingnotches 31, formed in the prongs of a fork shaped conductor member 3) toserve as a pivot between this fork shaped conductor member and theconductor member 2S, in addition to maintaining these two membersagainst sideway movement at this point. A tension spring 28 has one endhooked to the T-shaped screw threaded stud 29 and its other end to theforked shaped conductor member 30 a small distance from its free end, asshown, and like the conductor member 25, as above mentioned, is slottedlongitudinally in a manner to permit the free movement of this conductormember on each side of spring 28 from the non-operated position, shownin Fig. 2, to the operated position shown in Fig. 4.

The fork shaped conductor member 3), at its free end, is provided oneach side thereof with contact pieces 32 Vand 33 for vengaging thecontacts 34 and 3S, respectively,

carried by wire terminals and 21, upon the operation of plunger 13 forpivoting the conductor members 25 and 30 and consequently compressingthe compression spring 24. Accordingl to this construction it is to benoted that the tension spring 28, which is hooked'to screw threaded stud29 and to the conductor member 30, is tensioned to its maximum when-theconductor members and 30 are moved Vin a substantially straight line orcoaxial alignment by the operation of plunger member 13 which alignmentoccurs when the contacts 32 and 33 arepositioned at equal spacedrelation or distance from their respective co-operating contact pieces34 and 35 carried by the wire terminals 20 and 21.

Under the above mentioned condition the movement of plunger 13, to itsoperated position against the 'resistance of compression spring 24, iseffective to move the pivotal or hinged point of conductor members 25and 30, passed their so-called dead -line center which causes thetension spring 2S Vto impart a continued pivotal movement to theconductor member for engaging the contacts 33 and 35, as shown in Fig.4, in a quick or snap action independently of the movement of plunger13. The plunger 13 is returned to the non-operated position upon itsrelease eiected by the compression spring 24, which, in turn, causes thepivotal movement Yof conductor members 25 and 30 towards their normalnonoperated position and thereby reengaging the normally closed contacts32 and 34 under the tension of spring 28 when the conductor member 25,as shown in Fig. 2, reengages the T-shaped head of screw threaded stud29 serving as an adjustable stop for limiting the angle formed by theconductor members and the pressure between the contacts 32 and 34, andthe switch is now ready for a succeeding operation.

In the switch construction of the present invention, an importantfeature is the provision of the tension spring 28 for returning theconductor members 25 and 30 to normal, which spring may be tensioned soas to obtain any pressure contact value desired between the contacts32-34 and 33-35, as the case may be, in the operated and non-operatedpositions, which applicant has found practically impossible to obtain bythe use of ordinary leaf spring as practised in miniature switches nowin use.

Another important feature is in the making of the conductor members 25and 30 as far as practical of equal length between their pivotal pointsand the center of the contacts 32 and 33and of making such conductormembers of any desired rigidity to assure long life in operation and toavoid chatter in the closing of the contacts, while the use of purecopper in the manufacture of these operating parts has been found toconsiderably increase the current conducting characteristic of theswitch thus constructed and possess good machinability resulting inmaximum economy.

In the modication of the switch mechanism shown in Figs. 6 and 7, thehousing is formed of two vertical cornplemental lengthwise sections 40and 41, secured in assembled relation to each other, as by eyelets 42and 43, through which screws-not shownmay be inserted for securing theswitch to the machine part with which it may be used.

Each section is formed with registering cavities for slidably receivingthe plunger member 44, the pin 45 and the Wire terminals 46, 47 and 48,each of these terminals being provided with notches, as 49, registeringwith similarly shaped portions in the sections 40 and 41 for positivelyholding and readily locating the wire terminals 47 and 48 in spacedrelation to wire terminal 46 and thereby the contact pieces 51 and 52relative to contacts 53 and 54 carried by the wire terminals 47 and 48.

In this modification, as shown in Fig. 8, the tension spring 56 isconstructed in the form of a corrugated piano wire laying in planeperpendicular to the conductor members and 55 so as to permit a minimumwidth between the prongs of conductor members 50 and 55, the maximumWidth of which, in actual construction for practical reasons, do notexceed 'yle of an inch, while the transverse distance of the housingassembled does not exceed 1A of an inch maximum.

In the operation of the switch shown in Figs. 6 and 7, like that of theswitch mechanism shown in Fig. l, the operation of plunger 44 a fewthousandths of an inch from normal position is etective to move theconductor member 50 from the position shown in Fig. 7, passed the lineof maximum tension of spring 56 to a point in abutment against the wallportion, as 59, of the casing sections 40 and 41, assembled, suchmovement being effective to tension the spring 56 to a maximum to causethe pivotal movement of conductor member 55 independently of theoperation of the plunger 44 occurring when the pivotal point ofconductor members 50 and 55 has been moved and passed beyond theso-called dead center, the conductor members 50 and 55 being afterwardreturned to normal position by the then compressed spring 60, suchreturn movement occurring following the release of plunger 44, and theswitch is now ready for a succeeding operation.

What I claim is:

l. A switch mechanism comprising a base, two forked shaped conductormembers or' substantially equal length hinged to each other in end toend relation, a support embedded in said base for hinging the other endof one of said conductorr members, said support extending through saidbase to form a wire terminal, contacts carried by the other of saidconductor members at the free end thereof, a pair of wire terminalsembedded in said base and extending from both sides thereof, contactscarried by said terminals disposed for successive engagement by thecontacts carried by said other conductor member, a stud in said basedisposed between the prongs of said forked shaped conductor members, aspring tensioned betweeny said stud and the contacts carried by saidother conductor member for normally holding the latter in engagedposition with the contact carried by one of said wire terminals in saidpair, a plunger member operable'for actuating said hinged conductormembers to another position to a point passed their dead centeralignment longitudinally to cause the contacts carried by said otherconductor member to engage the contact of the other wire terminal insaid pair with a snap action under the tension of said spring, acompression spring disposed in coaxial relation to and compressed by theoperation of said plunger'member for returning said hinged conductormembers to normal upon the release of said plunger member to cause thecontacts carried by said other conductor member to reengage the rstmentioned terminal with a snap action effected by said tension spring.

2. In a switching device of the miniature type, a base of moldedinsulating material, two forked shaped conductor members of equal lengthhinged to eachother at one of their ends, a terminal embedded into saidbase having one of its ends forming a support for pivoting one of saidconductor members at its other end, contacts carried by the other ofsaid hinged conductor members at the free end thereof, an adjustablestud in said base disposed between the prongs of said forked shapedconductor members adjacent their pivotal point, a pair of Wire terminalsembedded in said base having contacts disposed for engagement with thecontacts carried by said other conductor member, a spring positionedbetween the prongs formed by said forked conductor members and normallytensioned Vbetween said stud and said contacts carrying conductormember, said stud having means forming a stop element for controllingthe pivotal movement of said hinged conductor members and the pressurebetween said contact carrying conductor member and one of said terminalsin said pair under the ,tension of said spring, a plunger memberoperable for actuating said singed conductor members to cause saidcontacts carrying conductor member to engage the other of said Wireterminals with a snap action under the tension of said spring, acompression spring disposed in coaxial relation to said plunger memberand compressed by the movement of the latter for actuating said hingedconductor members for reengaging said contact carrying conductor memberwith the rst mentioned wire terminal with a snap action effected underthe tension of the rst mentioned spring upon the release of said plungermember and means formed in said base forming a guide element for saidcompression spring.

3. In a switching device of the miniature type, a mounting, a pair ofwire terminals fitted in said mounting having contacts disposed insuperposed spaced relation to each other, another wire terminal fittedin said mounting having one of its ends forming a hinge element, aconductor member having one end hinged to said element and its free endterminating in the form of a fork, a stud member fitted in said mountingin position between the prongs of said forked conductor member, anotherconductor member'having a forked end pivotally engaging the fork shapedend of the Iirst mentioned conductor member and having contacts at itsfree end for alternatively engaging the contacts carried by the Wireterminals in saidpair, a tension spring disposed between the prongs ofsaid conductor members having one end hooked to said stud and its otherend to said contacts carrying conductor member adjacent the free endthereof, said spring being tensioned to normally cause the engagement ofone of the contacts carried by the last mentioned forked conductormember with the contact of one wire terminal in said pair, a plunger foractuating said conductor members against the tension of said spring tocause the engagement of said contact carrying conductor member with thecontact of the other wire terminal in said pair, a compression spring,guiding means for said compression spring formed in said mounting incoaxial alignment with said plunger and compressed by the movement ofthe latter for returning said pivoted conductor members to normal tocause the reengagement of the contacts carrying conductor member withthe first mentioned wire terminal with a snap action effected by saidtension spring, and stop means formed with said stud engaged by theconductor member hinged to said wire terminal for stopping the movementof both of said conductor members in normal non-operated position.

4. A switching device of the miniature type comprising a mounting, aWire terminal embedded into said mounting and having one of its endsforming a hinge element, a pair of forked shaped conductor members ofequal length hinged to each other, one of said members having itsopposite end pivoted to the hinge element of said wire terminal and theother of said conductor members having contacts at the free end thereof,a pair of wire terminals embedded into said mounting having contactsdisposed for successive engagement by the contacts at the free end ofthe last mentioned conductor member, a bushing embedded in saidmounting, a T shaped screw threaded stud engaging said bushing andforming a stop element, a tension spring having its ends hooked to thelast mentioned conductor member and to said T shaped stud between theprongs of said hinged conductor members and normally tensioned forholding said hinged conductor members pivoted against said stop elementin position to form an obtuse angle to cause a contact of the contactscarrying conductor member to engage the contact of one of said wireterminals with a pressure depending upon the adjusted position of said Tshaped stud and the action of said tension spring, a plunger member foractuating said hinged conductor members for reversing the angleformation thereof to cause the other contact of the contacts carryingconductor member to engage the contact of the other wire terminal with asnap action, a compression spring disposed in coaxial relation to saidplunger member and compressed by the operation of the latter forreturning said hinged conductor members to normal position forreengaging the first mentioned terminal with a snap action eiected bysaid tension spring upon the release of said plunger member, and meansformed in said mounting for holding said compression spring in saidrelation.

References Cited in the le of this patent UNITED STATES PATENTS2,326,874 Meuer Aug. 17, 1943 2,486,033 Kaminky Oct. 25, 1949 2,518,255Roeser Aug. 8, 1950 FOREIGN PATENTS 598,487 Germany June 11, 1934484,966 Canada July 15, 1952

